Driving mechanism for rotary drilling machines



J. J. GRAIN DRIVING MECHANISM FOR ROTARY DRILLING MACHINES Filed June 24. 1927 2 Sheets-Sheet 1 M H E R3 E m m N mm A . Jame W31. J. J. cRAsN L fi DRIVING MECHANISM FOR ROTARY DRILLING MACHINES Filed June 24, 1927 2 Sheets-Sheet 2 J INVENTOR A/ E N 4 28 0H d 6 /7 ATTORNE-YS Patented Jan. 6, 1931 E I QFFICE JOHLI J. GRAIN, OF WATERBUR Y, CONNECTICUT, ASSIGNOR TO THE WATERBURY TOOL COMPANY, OF WATERBURY, CONNECTICUT, A CORPORATION OF CONNECTICUT DRIVING- MECHANISM FOR ROTARY DTRILLING MACHINES Application filed June 24,

The principal object of this invention is to.

provide a new and improved construction for the driving mechanism of rotary drilling machines of the type employed for the drilling of oil wells. In the drilling of oil wells, great differences occur in the resistances offered both to the rotation of the drill and the feed thereof, because of the different strata of material i. e. rock, sand, mud, clay, 1 etc. of which the earth is composed. Consequently it has been a problem of v great difficulty to provide a driving mechanism ca pable of compensating for the differences in resistances which the drill must overcome.

is In order to secure the best results it is desirable that the driving mechanism be so constructed that first: the drill will be subjected to an approximately constant uniform torque thereby avoiding the danger of its breaking or twisting off, second, that the rate of feed will be governed automatically by the resistance encountered by the drill, and third, the drill will be automatically raised or relicved when sticking thereof occurs.

: The present invention has for its object to produce a driving mechanism that will fulfill the conditions above enumerated. A further object is toprovide a hydraulic speed gear equipment adapted to be so combined with the drilling machine that the apparatus will operate automatically to compensate for differences in resistance offered to the drill by different m aterials. Other more specific objects will appear fromthe description hereinafter and the features of novelty will be pointed out in the claims.

In the accon'ipanying drawings forming a part hereof Fig. 1 is a plan view of a rotary drilling machine equipment embodying the principles of my invention, Fig. 2 is a side elevation, and Fig. 3 is a side elevation partly in'section of an A-end unit of a hydraulic speed gear of the type above described.

As shown in the drawings, the numeral 10 indicates the base of the drilling machine proper, which base has rotatably mounted therein the rotary drill table 11. The table 11 has secured thereto a bevel gear 12 driven by the bevel pinion 13; the latter being secured to the shaft 14 of a hydraulic gear! is suspended by the eye bracket 18.

1927. Serial No. 201,073.

construction of devices of the type to which this invention relates, is provided with a non-circular, central, through, aperture in which is slidably received the drill rod 16.

Secured to the lower end of said drill rod is the drill bit 17 while the upper end of said rod has'fastened thereto an eye bracket 18 with which the drill hoisting tackle is engaged.

Any suitable mechanism may be employed for the hoisting tackle; as shown such tackle consists of a pair of pulley blocks 19, 20, through which the hoisting cable 21 is trained, the block 19 being provided with the usual hook 19'' from which the drill rod 16 One end of the cable 21 is anchored to the block 19 and the other end thereof is trained about the winch 22. The winch 22 is driven, through the gears 23 by means of a small hydraulic gear unit or A-end 24, having an adjustable control shaft 25.

The B-end 15 and the small A-end 24 are connected in parallel to the pipe lines 26 and 27 through which fluid under pressure is circulated by a. main pump unit or A-end 28, the latter being connected with said pipe lines by the connecting pipes 29, 30. The main A-end 28 is provided with an adjustable control shaft 31 and is. driven by any suitable means such as an electric motor 32.

As shown in Fig. 3 of the drawings each gear unit comprises a rotary barrel 35 having a plurality of cylinders 36 formed therein, in which cylinders, pistons 37 are mounted for reciprocation. The pistons 37 are connected by means of the piston rods 38 with a member 39, known in the art, as a swashplate. The swash-plate is mounted for rotation within a tilting box 40 having a projecting stub shaft 41. To the end ofthe stub shaft 41 is connected the lower end of a control shaft 42, the upper end of which is threaded and projects through the casing of the unit. Engaged upon the threaded upper end of the. control shaft 42 is a nut 43 having a hand wheel portion 44' 3. mm?!) 9f the hand wheel 44 and nut 43 will produce a vertical' adjustment of the control shaft and a corresponding change in the inclination of the tilting boxand swash-plate. When the -tilting box is perpendicular tothe axis of rothe inclination the greater the stroke. In-

clination of the tilting box in one direction causes the fluid to be pumped by the pump unit in a given direction whereas inclination of the box in the opposite direction causes the direction of the flow of the fluid to be reversed. In the motor unit of a gear of this type, the tilting box is usually held at a fixed angle of inclination and therefore the adjustable control shaft is not ordinarily used with tht motor unit. In the pump unit however, the adjustable control shaft 42 is employed. An example of the type of hydraulic gear is disclosed in' United States Patent #925,148 of June 15, 1909, Harvey D. lVilliams, variable speed gear The operation is as follows: The electric motor 32 being placed in rotation, will drive the main A-end 28 by means of which fluid will be pumped to the pipe lines 26, 27 at a rate depending upon the setting of the control shaft 31. Fluid under pressure is circulated from the main A-end 28 through the pipes 26, 27, 29 and 30 to the small A-end 24 and the B-end 15. The B-end 15 will be driven by such fluid and its shaft 14 will rotate, through the gears 12, 13, the drill table 11 and thedrill rod 16. For ordinary drilling the control shaft 25 of the A-end 24 will be set so that a suflicient tension will be maintained on the cable 21 to offset or balance the weight of the drill rod to the required extent according to the amount of feeding pressure desired. As the drill moves downwardly under such pressure and the cable 21 pays out thus rotating the.winch drum, and the shaft of the A-end 24, the latter acts as a pump and feeds fluid under pressure to the pipe lines 26, 27. If the drill should stick, the pressure ofthe fluid in the B-end 15 obviously will mount and the fluid, following the lines of least resistance will be pumped to the A-end 24 driving it as a motor and causing the winch to operate the hoisting tackle in a direction to raise or relieve the drill. When the drill meets with but slight resistance and runs down more rapidly, the overhauling of the A-end 24 by the winch causes said A-end 24 to operate as a pump and to deliver fluid under pressure to the line thus causing the B-end 15 and drill to be rotated more rapidly, while, when harder, or

more resistant material is encountered, the drill will not run down as rapidly, therefore, thmpumping, action of the A-end24 will decrease or will be neutralized, and as the pressure in the B-end 15 increases the A-end 24 will operate as a motor to raise the drill. It will thus be. seen that if the torque required to rotate the drill increases, the increased oil pressure will operate, back through the line to the A-end 24, to raise or relieve the drill and prevent increase of the torque beyond a predetermined amount whereas when the drill works easily and the oil pressure lowers, the drill will descend more rapidly thus tending again to restore the torque to its normal amount. Consequently, an approximately uniform, and accurately predetermined torque can be maintained upon the drill, which torque is controllable by the adjustment or setting of the control shaft 25 of the A-end 24 while at the same time the normal speed of rotation of the drill can be regulated by the adjustment of the control shaft 31 of the A-end 28. As the well becomes deeper and the Weight of the drill is increased by the use of additional lengths of drill rod, the number of leads in the hoisting tackle can be increased so that constant oil pressure can be maintained with a variation in the control setting of the small A-end 24 of. not much more than 2 to 1, that is, from full stroke to half stroke. Within this range the A-end 24 will work satisfactorily both as a hydraulic motor and as a hydraulic pump.

While I have shown the invention as applied to a rotary, oil well, drilling machine it will be understood that the invention is not limited in its application to this specific type of machine but that it may be used in other installations wherein it is desirable to obtain a balanced or proportional relationship be tween torque and feed. It will also be understood that many changes, variations and modifications may be resorted to without departing from the spirit of the invention.

I claim:

1. The combination with adrilling machine having a rotar drill and a hoisting mechanism, ofca flui pressure pump and a pair of fluid pressure gear units connected in parallel with said pump, one of said units being connected with said drill for rotating it and the other of said units being connected with said hoisting mechanism and being operated convertibly as a pump or as a motor auto- ,matica-lly in accordance with the resistance the longitudinal movement of said tool, of a main fluid pressure pump, and piping connections between said pump and units whereby the resistance encountered to the rotation of said tool will be communicated through said fluid to the said other of said units to produce rotation thereof. a

3. The combination with a rotary cutting tool, of a pair of fluidpressure gear units operatively associated with said tool, one of said units exerting a torque upon said tool and the other governing the rate of feed of said tool to the work, and pipe connections between said units for causing the operating fluid to be circulated to said units in accordance with the resistances offered to the movements of said tool.

4. The combination with a cutting tool, of a rotary fluid pressure actuated driving gear to rotate said tool, and means to cause said gear to maintain a substantially uniform torque upon said tool, said means including a second rotary fluid pressure actuated drivin gear for regulating the rate of feed of sa1d tool to the work.

5. The combination with a cutting tool, of a rotary fluid pressure actuated driving gear to rotate said tool,and means to cause said gear to maintain a substantially uniform torque upon said tool, said means includin a second rotary fluid pressure actuated driving gear of adjustable effect for regulating the rate of feed of said tool to the work.

6-.- The combination with a rotary cutting tool, of a rotary fluid pressure. actuated driving gear to rotate said tool, a second rotary fluid pressure actuated gear for regulating the feed of said tool to the work, a

common pump for supplying fluid under pressure to sa1d driving gears and pipe connections interconnecting both of said gears and said pump,

7. The combination with an oil well drilling machine having a rotar drill and hoisting mechanism therefor, o a fluid pressure actuated motor associated with said drill for rotating it, a fluid pressure actuated gear unit adapted to function as a motor or as a pump, operatively associated with said hoisting mechanism, a pump for circulating fluid under pressure to said motor and gear unit and piping interconnecting said motor, said gear unit and said pump.

8. The combination with an oil well drilling machine having a rotary drill and hoisting mechanism therefor, of a fluid pressure actuated motor associated with said drill for rotating it, a second fluid pressure actuated device, capable of being operated either as a pump or as a motor, connected with said hoisting mechanism, and a pump for supplying fluid under pressure simultaneously to said motor and to said device, said device being provided with-means for varying its effect.

9. The combination with an'oil well drill ing machine having a rotary drill and hoisting mechanism therefor, of a fluid pressure rotating it, a second fluid pressure actuated device, capable-of being operated either as a pump or as a motor, connected with said hoistin mechanism, and a pump for supplying fluid under ressure simultaneously to sa1d motor and to said device, said pump and said device each being provided with ad'ustable controlling means, the variation 0 the controlling means for said pump efl'ecting speed changes in the rotation of said drill and the variation of the controlling means for (slaiclll device efle'cting the rate of feed of said 10. The combination with an oil well drilling machine having a rotary drill and hoisting mechanism therefor, of a fluid pressure actuated motor associated with said drill for rotating it, a second fluid pressure actuated device, capable of being operated either as a pump or as a motor, connected with said hoisting mechanism, and a pump for supplying fluid under pressure simultaneously'to said motor and to said device, said pump and said device each being provided with adjustable controlling means, the variation of the controlling means for said pump eifecting speed changes in the rotation, of said drill and the variation of the controlling means for said device effecting the rate of feed of said drill and piping interconnecting said pump motor and device whereby a mutual interdependence of operation of said motor and device is secured and a substantially uniform torque is imparted to said drill.

11. The combination with an oil well drilling machine having a rotary drill and hoisting mechanism therefor, of a fluid pressure actuated motor associated with said drill for rotating it, a fluid pressure actuated device capable of operating either as a pump or as a motor, operatively associated with said hoisting mechanism, suction and pressure pipe lines connecting said motor and said device whereby variations of the pressure conditions in said motor due to changes of resistance offered to the rotation of said drill will be communicated through the fluid in said pipe lines to said device, and a pump for supplying fluid under pressure to said motor.

In testimony whereof I have hereunto set my hand.

JOHN J. GRAIN. 

